Fibroids

Published by Bupa's Health Information Team, June 2010.

This factsheet is for women who have fibroids, or who would like information about them.

Fibroids are non-cancerous growths of the womb (uterus). They are also known as uterine myomas or leiomyomas.

About fibroids

Fibroids are growths enclosed in capsules attached to the wall of your womb. They don't spread to other parts of your body.

Fibroids are very common - more than two in five women have fibroids. However, most of these women don't ever get any symptoms.

You may have only one fibroid or you may have many fibroids of different sizes. Fibroids range from being too small to be seen with the naked eye to around the size of a basketball.

Fibroids are named according to where they are found in your womb.

• Intramural fibroids grow within the muscular wall of your womb.
• Subserous fibroids grow from the outside wall of your womb into your pelvic cavity. They can become very large.
• Submucosal fibroids grow from the inner wall of your womb into the space inside your womb.
• Pedunculated fibroids grow from the outside of your womb. These fibroids are almost free of the wall of your womb and are only attached by a narrow stalk.

Fibroid growth is very slow and can be stimulated by hormones, especially oestrogen. Fibroids tend to become smaller and reduce in number when your oestrogen levels fall, such as after the menopause.

Symptoms of fibroids

Fibroids don't usually cause symptoms. However, you may get one or more of the symptoms listed below, often depending on where the fibroid is within your womb.

• Heavy periods, sometimes leading to anaemia. Up to one in three women with fibroids have heavy periods.
• Pain in your tummy (abdomen).
• Swelling in your pelvic area.
• Passing urine more often than normal. This can happen if a fibroid is pressing on your bladder.
• Constipation, if a fibroid is pressing on your rectum.

You can get severe pain if a fibroid that is growing on a stalk twists or if a fibroid outgrows its blood supply causing it to break down, but this is rare.

Complications of fibroids

Most women with fibroids can have a normal pregnancy and delivery; however there can be some complications.

Submucosal fibroids can affect the shape and internal environment of your womb, which can make it more difficult for you to become pregnant.

Fibroids can sometimes cause problems such as miscarriage, premature labour and bleeding, but this is rare.

If you're pregnant and have fibroids, your GP may refer you to an obstetrician (a doctor who specialises in pregnancy and childbirth) for specialist care.

Causes of fibroids

The reasons why women get fibroids aren't known. Although oestrogen seems to make fibroids grow, it's not thought to be responsible for their initial development.

You're more likely to get fibroids if you:

• are in your 30s or 40s
• are overweight
• are African-Caribbean - African-Caribbean women are three times more likely than Caucasian women to get fibroids
• have no children
• had an early puberty

Diagnosis of fibroids

Most women with fibroids have no symptoms, so the fibroids often go undetected. Sometimes they are found during a routine gynaecological (vaginal) examination. If you have symptoms, such as pain or heavy periods, your doctor may do the following tests.

• An internal examination to check the size of your womb. An enlarged womb indicates that you may have fibroids.
• An ultrasound scan. This uses sound waves to produce an image of part of your womb and can confirm if you have fibroids.
• An MRI scan. This uses magnets and radio waves to produce images of the inside of your womb.

Treatment of fibroids

If you don't have any symptoms, or if your symptoms are mild, you won't need treatment.

If you have more severe symptoms, there is a range of treatments available. Your doctor will explain which treatment is most suitable for you.

Medicines

There is no medicine that cures fibroids. However, hormone-based treatments can help relieve your symptoms.

Treatment with medicines called gonadotropin-releasing hormone analogues (GnRH analogues) can lower your oestrogen level. This usually shrinks fibroids.

If you're having surgery to remove fibroids, you may be prescribed GnRH analogues such as goserelin or leuprorelin acetate, to take for three to four months before your operation to make it easier for your surgeon to remove fibroids.

GnRH analogues can cause side-effects including hot flushes and, if used in the long-term, osteoporosis (thinning of the bones). Therefore, you can only take GnRH analogues for a maximum of six months. Your doctor may prescribe progestogen hormone replacement therapy medicines or a medicine called tibolone for you to take at the same time as GnRH analogues. This is to reduce the chances of you having side-effects.

Surgery

There are a number of surgical options for treating fibroids, including those outlined below.

Uterine artery embolisation (UAE)
This procedure blocks the blood supply to a fibroid, causing it to shrink. It's performed under local anaesthesia, meaning that feeling in the area will be completely blocked but you will stay awake during the operation. UAE gives relief from symptoms such as bleeding and pain for at least six in every 10 women treated.

Endometrial ablation or resection
Endometrial ablation is a procedure to remove most of the lining of your womb or to destroy or remove an individual fibroid using energy such as microwaves or heat. During an endometrial resection, the lining of your womb or the fibroid is actually cut away.

Myomectomy
A myomectomy is an operation to remove fibroids, leaving your womb in place. It may be done through a cut in your tummy, or sometimes it may be possible for your surgeon to use keyhole surgery. Myomectomy is usually only offered to women who would like the option to become pregnant in the future. Because your womb isn't removed there is a chance that more fibroids will grow in the future, so you may need to have further treatment.

Hysterectomy
A hysterectomy is a major operation to remove your entire womb, usually via a 'bikini-line' cut in your abdomen or, if the fibroids aren't too large, via your vagina. It's not possible to get pregnant after a hysterectomy.

For answers to frequently asked questions on this topic, see Common questions.

For sources and links to further information, see Resources.